Rat tissues (10 mg each) were excised and stored at room temperature for up to 4 hours in phosphate-buffered saline (PBS) or RNAlater RNA Stabilization Reagent (RNAlater). At the indicated times, RNA was isolated using the RNeasy Protect Mini Kit. Total RNA was used for quantitative RT-PCR using the QuantiTect Probe RT-PCR Kit and primers and probe specific for the transforming growth factor β (TGF-β) gene or the tumor necrosis factor α (TNF-α) gene. Analyses were carried out in triplicate on the ABI PRISM 7700 Sequence Detection System. The change in threshold cycle (CT) is shown, relative to the CT at time zero.|RNA was isolated from fresh rat kidney samples after 0, 5, 10, 15, 30, and 60 minutes, using either standard procedures (Unstabilized) or RNeasy Protect Kits (Stabilized). The RNA isolated was analyzed by agarose gel electrophoresis and expression of GAPDH was examined using northern blot analysis. M: markers.|Total RNA was isolated from tissue samples stored in RNAlater RNA Stabilization Reagent. [A] Rat lung tissue was stored under the indicated conditions. RNA was analyzed on a formaldehyde agarose gel and northern blot (GAPDH-probed). [B] Stabilized mouse liver tissue was subjected to freeze–thaw cycles (-20°C/25°C). C: control tissues frozen in liquid nitrogen and stored at -80°C.|

Once a biological sample is harvested, its RNA becomes extremely unstable. The innovative, aqueous RNAlaterRNA Stabilization Reagent quickly permeates tissues resulting in immediate stabilization of the RNA and preservation of the RNA expression pattern. Gene induction or down-regulation triggered by sample manipulation is also prevented, allowing accurate analysis of gene expression.

Procedure

For RNA protection and sample storage, tissue samples are submerged in an appropriate volume of RNAlater RNA Stabilization Reagent immediately after harvesting. RNAlater TissueProtect Tubes provide premeasured volumes of RNAlater RNA Stabilization Reagent in reclosable tubes for convenient handling and sample storage. The reagent preserves RNA for up to 1 day at 37°C, 7 days at 18–25°C, or 4 weeks at 2–8°C, allowing processing, transportation, storage, and shipping of samples without liquid nitrogen or dry ice. Alternatively, the samples can also be placed at –20°C or –80°C for archival storage.

Applications

Animal and human tissues stabilized in RNAlater RNA Stabilization Reagent can be efficiently disrupted using QIAGEN instruments for sample disruption, and used with QIAGEN kits for: